Currently, a global analysis of the information available on the relative composition of the floral scents of a very diverse variety of plant species is missing. Such analysis may reveal general patterns on the distribution and dominance of the volatile compounds that form these mixtures, and may also allow measuring the effects of factors such as the phylogeny, pollination vectors, and climatic conditions on the floral scents of the species. To fill this gap, we compiled published data on the relative compositions and emission rates of volatile organic compounds (VOCs) in the floral scents of 305 plant species from 66 families. We also gathered information on the groups of pollinators that visited the flowers and the climatic conditions in the areas of distribution of these species. This information allowed us to characterize the occurrence and relative abundances of individual volatiles in floral scents and the effects of biotic and climatic factors on floral scent. The monoterpenes trans-β-ocimene and linalool and the benzenoid benzaldehyde were the most abundant floral VOCs, in both ubiquity and predominance in the floral blends. Floral VOC richness and relative composition were moderately preserved traits across the phylogeny. The reliance on different pollinator groups and the climate also had important effects on floral VOC richness, composition, and emission rates of the species. Our results support the hypothesis that key compounds or compounds originating from specific biosynthetic pathways mediate the attraction of the main pollinators. Our results also indicate a prevalence of monoterpenes in the floral blends of plants that grow in drier conditions, which could link with the fact that monoterpene emissions protect plants against oxidative stresses throughout drought periods and their emissions are enhanced under moderate drought stress. Sesquiterpenes, in turn, were positively correlated with mean annual temperature, supporting that sesquiterpene emissions are dominated mainly by ambient temperature. This study is the first to quantitatively summarise data on floral-scent emissions and provides new insights into the biotic and climatic factors that influence floral scents.

当前，缺乏关于非常多种植物物种的花香的相对组成的可用信息的全局分析。此类分析可以揭示形成这些混合物的挥发性化合物的分布和优势的一般模式，还可以测量诸如系统发育，授粉载体和气候条件等因素对物种花香的影响。为了填补这一空白，我们汇编了已公布的数据，涉及来自66个科的305种植物的花香中挥发性有机化合物（VOC）的相对组成和排放速率。我们还收集了有关访问这些花的传粉媒介群的信息以及这些物种分布区域的气候条件。这些信息使我们能够表征花香中单个挥发物的出现和相对丰度，以及生物和气候因素对花香的影响。单萜反式-β-烯丙二胺和芳樟醇和苯甲醛苯甲醛是最丰富的花香型挥发性有机化合物，在花型混纺中普遍存在和占优势。在整个系统发育中，花卉VOC的丰富度和相对组成是中等保留的性状。对不同传粉媒介种类和气候的依赖也对花卉挥发性有机化合物的丰富度，组成和排放率产生了重要影响。我们的结果支持以下假设：关键化合物或源自特定生物合成途径的化合物介导主要授粉媒介的吸引力。我们的结果还表明，在干燥条件下生长的植物花卉混合物中普遍存在单萜，这可能与单萜排放保护植物在整个干旱时期免受氧化胁迫以及在中等干旱胁迫下其排放增加的事实有关。反过来，倍半萜与年平均温度呈正相关，支持倍半萜的排放量主要由环境温度决定。这项研究是第一个定量总结花香排放量数据的方法，并为影响花香的生物和气候因素提供了新见解。这可能与单萜排放保护植物在整个干旱时期免受氧化胁迫以及在中等干旱胁迫下其排放增加的事实有关。反过来，倍半萜与年平均温度呈正相关，支持倍半萜的排放量主要由环境温度决定。这项研究是第一个定量总结花香排放量数据的方法，并为影响花香的生物和气候因素提供了新见解。这可能与单萜排放保护植物在整个干旱时期免受氧化胁迫以及在中等干旱胁迫下其排放增加的事实有关。反过来，倍半萜与年平均温度呈正相关，支持倍半萜的排放主要由环境温度决定。这项研究是第一个定量总结花香排放量数据的方法，并为影响花香的生物和气候因素提供了新见解。